Process for producing solanone, norsolanadione and intermediates therefor

ABSTRACT

Described is a process for preparing solanone and norsolanadione wherein in preparing solanone, the compound having the structure: ##STR1## or a mixture of compounds defined according to the structure: ##STR2## is reacted with methyl lithium and the resulting intermediate is hydrolyzed and the resulting compound is dehydrated and wherein in preparing norsolanadione this compound or mixture of compounds is reacted with ethylene glycol or propylene glycol thereby forming a ketal and the resulting ketal is reacted with methyl lithium and the resulting intermediate is then hydrolyzed in the presence of acid in which one of the dashed lines represents a carbon-carbon single bond and the other of the dashed lines represents a carbon-carbon double bond.

This is a divisional of application Ser. No. 511,944, filed 7/8/83, nowU.S. Pat. No. 4,489,009, which, in turn, is a divisional of applicationfor U.S. Letters Patent, Ser. No. 357,158 filed on 3/11/82, now U.S.Pat. No. 4,412,083 issued 10/25/83.

BACKGROUND OF THE INVENTION

Solanone is known as a useful tobacco flavorant and flavor enhancer. Itis a mixture consisting primarily of the compound: ##STR3## and, inaddition, a small amount of the compound having the structure: ##STR4##

Norsolanadione is another compound known to be useful as a tobaccoflavorant and in augmenting or enhancing the aroma and taste of smokingtobacco. Norsolanadione has the structure: ##STR5## Both norsolanadioneand solanone have been previously synthesized using cumbersome,economically unfeasible reactions, e.g. reactions including the Wittigor Emmons reaction.

The compound having the structure: ##STR6## has been isolated fromBurley tobacco flavor as set forth in Chem. Abstracts 1974, 35704g andin the article by Demole et al, Helv. Chim. Acta, 1974, 57(1) pages192-4. This material known as "solanone hydrate" is also shown to besynthesized in Chem. Abstracts 85:108821n via a complex, multi-stepsynthesis.

The present invention provides an efficient, low cost synthesis forpreparation of solanone, norsolanadione and solanone hydrate having thestructure: ##STR7##

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the GLC profile for the reaction product of Example IIcontaining the compounds having the structures: ##STR8## (conditions:SE-30 column programmed at 100°-220° C. at 8° C. per minute).

FIG. 2 is the GLC profile of the reaction product prior to hydrolysis ofExample II containing the compounds having the structures: ##STR9##

FIG. 3 is the GLC profile for the reaction product of Example IIsubsequent to hydrolysis (crude reaction product) having the structure:##STR10##

FIG. 4A is the GLC profile for bulked fractions 4-11 of the distillationproduct of the reaction product of Example II containing the compoundhaving the structure: ##STR11##

FIG. 4B is the GLC profile for fraction 2 of the distillation product ofthe reaction product of Example II containing the compound having thestructure: ##STR12##

FIG. 5 is the GLC profile for the crude reaction product of Example IIIcontaining the compounds having the structures: ##STR13##

FIG. 6 is the GLC profile for bulked fractions 1-4 of the distillationproduct of the reaction product of Example III containing the compoundhaving the structure: ##STR14##

FIG. 7A is the GLC profile for the crude reaction product of Example Vcontaining the compound having the structure: ##STR15##

FIG. 7B is the GLC profile for the distillation product of the reactionproduct of Example V containing the compound having the structure:##STR16## (conditions: SE-30 column programmed at 100°-220° C. at 8° C.per minute).

FIG. 8 is the infra-red spectrum for the compound produced according toExample V having the structure: ##STR17##

FIG. 9 is the GLC profile for the crude reaction product of Example VIcontaining the compound having the structure: ##STR18##

FIG. 10 is the GLC profile for the reaction product of Example VIIcontaining the compound having the structure: ##STR19## (conditions:SE-30 column programmed at 100°-220° C. at 8° C. per minute).

FIG. 11 is the infra-red spectrum for the compound having the structure:##STR20## produced according to Example VII.

FIG. 12 is the GLC profile for the reaction product of Example VIIIcontaining the compound having the structure: ##STR21##

FIG. 13 is the infra-red spectrum for the compound having the structure:##STR22## produced according to Example VIII.

FIG. 14 is the GLC profile for bulked fractions 6-10 of the distillationproduct of the reaction product of Example XI containing the compoundshaving the structures: ##STR23##

FIG. 15 is the GLC profile for the reaction product of Example Xcontaining the compound having the structure: ##STR24##

FIG. 16 is the NMR spectrum for the compound of Peak 41 of FIG. 15 forthe compound having the structure: ##STR25##

FIG. 17 is the NMR spectrum for the compound produced according toExample XI having the structure: ##STR26##

FIG. 18 is the infra-red spectrum for the reaction product of ExampleXII containing the compound having the structure: ##STR27##

FIG. 19 is the mass spectrum for fraction 3 of the distillation productof Example XII containing the compound having the structure: ##STR28##

FIG. 20 is the GLC profile for the reaction product of Example XIIIcontaining the compound having the structure: ##STR29##

FIG. 21 is the GLC profile for the reaction product of Example XIVcontaining the compound having the structure: ##STR30##

FIG. 22 is the NMR spectrum for fraction 5 of the distillation productof the reaction product of Example XIV containing the compound havingthe structure: ##STR31##

FIG. 23 is the infra-red spectrum for fraction 5 of the distillationproduct of the reaction product of Example XIV containing the compoundhaving the structure: ##STR32##

FIG. 24 is the GLC profile for the crude reaction product for Example XVcontaining the compound having the structure: ##STR33## (conditions:Carbowax column programmed at 150°-220° C. at 8° C. per minute).

FIG. 25 is the infra-red spectrum for the compound having the structure:##STR34## produced according to Example XV.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is the GLC profile for the reaction product of Example II priorto hydrolysis. The peak indicated by reference numeral "1" is the peakfor the compound having the structure: ##STR35## The peak indicated byreference numeral "2" is for the compound having the structure:##STR36## The peak indicated by the reference numeral "3" is for thecompound having the structure: ##STR37## The conditions for carrying outthis GLC profile are SE-30 column programmed at 100°-220° C. at 8° C.per minute.

FIG. 2 is the GLC profile for the reaction product of Example II priorto hydrolysis. The peak indicated by reference numeral "11" is the peakfor the compound having the structure: ##STR38## The peak indicated bythe reference numeral "12" is for the compound having the structure:##STR39## The conditions for this GLC profile are SE-30 columnprogrammed at 100°-220° C. at 8° C. per minute.

FIG. 5 is the GLC profile for the crude reaction product of Example III.The peak indicated by reference numeral "21" is for the compound havingthe structure: ##STR40## The peak indicated by reference numeral "22" isfor the compound having the structure: ##STR41## The peak indicated byreference numeral "23" is for the compound having the structure:##STR42## The peak indicated by reference numeral "24" is for thecompound having the structure: ##STR43##

FIG. 14 is the GLC profile for bulked fractions 6-10 of the distillationproduct of the reaction product of Example IX (conditions: Carbowaxcolumn programmed at 100°-220° C. at 8° C. per minute). The peakindicated by reference numeral "31" is the peak for the compound havingthe structure: ##STR44## The peak indicated by reference numeral "32" isfor the compound having the structure: ##STR45## The peak indicated byreference numeral "33" is for the compound having the structure:##STR46##

FIG. 15 is the GLC profile for the crude reaction product of Example X.The peak indicated by reference numeral "41" is for the compound havingthe structure: ##STR47##

THE INVENTION

Our invention covers a process using novel chemical intermediates forpreparing solanone hydrate defined according to the structures:##STR48## solanone, defined according to the structure: ##STR49## andnorsolanadione having the structure: ##STR50## Although these compoundsmay be produced in substantially pure form and are so produced herein,the economics of these processes are such that the compounds areproduced in admixture with other isomers thereof.

Solanone, solanone hydrate and norsolanadione are produced according toprocesses using novel intermediates defined according to the genericstructure: ##STR51## wherein X represents moieties defined according tothe structures: ##STR52## wherein R is hydrogen or methyl; and wherein Yis one of the moieties: ##STR53## with the provisos that:

(i) when Y is the moiety having the structure: ##STR54## then X is themoiety having the structure: ##STR55##

(ii) when X is the moiety having the structure: ##STR56## then Y is themoiety having the structure: ##STR57## and wherein one of the dashedlines is a carbon-carbon single bond and the other of the dashed linesis a carbon-carbon double bond. Examples of structures of the novelintermediates of our invention are as follows: ##STR58##

It is intended that the foregoing structures not only cover ketones inthose cases but their corresponding enols as well, for example thosehaving the structure: ##STR59## which exist in equilibrium with saidketones.

In preparing the novel intermediate having the structure: ##STR60## ormixture of novel intermediates having the structures: ##STR61## whereinin the mixture one of the dashed lines is a carbon-carbon double bondand the other of the dashed lines is a carbon-carbon single bond whichintermediates are used for producing all three useful tobacco flavoraugmenting or enhancing compounds, solanone, solanone hydrate andnorsolanadione. Isovaleraldehyde having the structure: ##STR62## isreacted with the compound having the structure: ##STR63## in order toproduce the compound having the structure: ##STR64## according to thereaction sequence: ##STR65## The resulting compound having thestructure: ##STR66## is then reacted with acrylonitrile therebyproducing two compounds having the structures: ##STR67## according tothe reaction sequence: ##STR68## The compounds having the structures:##STR69## are then hydrolyzed to produce the aldehyde defined accordingto the structure: ##STR70## as well as the starting material having thestructure: ##STR71## according to the reaction sequence: ##STR72##

The resulting aldehyde having the structure: ##STR73## is then reactedwith acetone via an aldol condensation reaction thereby forming amixture of ketones having the structures: ##STR74## which can beseparated into its component compounds or retained "as is". The desiredcomponent compound of the mixture having the structure: ##STR75## is thecompound having the structure: ##STR76## (wherein in the mixture one ofthe dashed lines is a carbon-carbon double bond and the other of thedashed lines is a carbon-carbon single bond).

This reaction is as follows: ##STR77##

The aldol condensation for the reaction of acetone with the aldehyde iscarried out using the standard aldol condensation basic catalyst such assodium hydroxide, potassium hydroxide, barium hydroxide or calciumhydroxide at temperatures in the range of from about 30° C. up to about60° C. The most preferred catalyst is barium hydroxide. The mole ratioof the aldehyde: acetone may vary from about 1:6 to about 1:1aldehyde:acetone. When using a sodium hydroxide catalyst, it ispreferred that the temperature of reaction be about 50°-60° C. Whenusing potassium hydroxide, it is preferred that the reaction temperaturebe 30°-45° C. When using barium hydroxide, it is preferred that thereaction temperature be 45°-60° C.

The mole ratio of base, e.g. sodium hydroxide, potassium hydroxide,barium hydroxide or calcium hydroxide:aldehyde reactant may vary fromabout 0.05:1 up to about 1:1. Actually, the aldol condensation reactionis a two-step reaction; the first reaction producing the actual "aldol"and the second reaction to produce the unsaturated keto-nitrile mixturehaving the structure: ##STR78## wherein in the mixture, in each of thecompounds, one of the dashed lines is a carbon-carbon double bond andthe other of the dashed lines is a carbon-carbon single bond: ##STR79##wherein M is alkali metal and M' is alkaline earth metal and wherein oneof the dashed lines in the compounds of the mixture formed is acarbon-carbon double bond and the other of the dashed lines in thecompounds of the mixture formed is a carbon-carbon single bond.Accordingly, the "aldol" intermediate having the structure: ##STR80## isalso contemplated as one of the novel intermediates of this invention.In carrying out the dehydration of the compound having the structure:##STR81## in order to form the compounds defined according to thestructure: ##STR82## (mixture, wherein in the mixture in each of themolecules, one of the dashed lines is a carbon-carbon double bond andthe other of the molecules is a carbon-carbon single bond). Examples ofacids which can be used are acetic acid and oxalic acid. Thus, theionization constant of the acid must be sufficient to dehydrate thehydroxyl group yet not hydrolyze the nitrile moiety. More specifically,the hydronium ion concentration must be high enough to give rise to adehydration but low enough not to hydrolyze the nitrile moiety to acarboxylic acid.

In producing solanone from the compound having the structure: ##STR83##or from the mixture of compounds defined according to the structure:##STR84## the nitrile ketone is first reacted with methyl lithium toform an organometallic intermediate defined according to the structure:##STR85## This organometallic intermediate is then hydrolyzed in thepresence of acid to form solanone hydrate defined according to thestructure: ##STR86## taken alone or in admixture with the compounddefined according to the structure: ##STR87## As stated in the"Background of the Invention", solanone hydrate is a known tobaccoflavorant and is useful in augmenting or enhancing the aroma or taste ofsmoking tobacco both prior to and on smoking in the main stream and theside stream. The solanone hydrate thus can be used "as is" or can bedehydrated to form compounds defined according to the structures:##STR88## A small amount of the compound defined according to thestructure ##STR89## is also formed from dehydration of the compoundhaving the structure: ##STR90##

In carrying out the reaction of the compound having the structure:##STR91## or the mixture of compounds defined according to thestructure: ##STR92## in order to produce the intermediate definedaccording to the structure: ##STR93## or the mixture of intermediatesdefined according to the structures: ##STR94## according to thereaction, for example: ##STR95## the methyl lithium is preferably formedin situ as by reaction of lithium metal with methyl bromide in thepresence of an inert solvent such as anhydrous diethylether. Thereaction of the methyl lithium with the nitrile having the structure:##STR96## or the mixture of nitriles having the structure: ##STR97##preferably takes place in the presence of an inert solvent such astoluene or xylene. The temperature of reaction may vary from about 0° C.up to about 60° C. but most preferably and conveniently, the temperatureof reaction is at ambient conditions, e.g. 20°-30° C. at atmosphericpressure. There is no need to operate the reaction at pressures higheror lower than atmospheric since no increase in the yield or conversionoccurs at higher or lower pressures. The mole ratio of methyllithium:nitrile having the structure: ##STR98## or nitrile mixturedefined according to the structure: ##STR99## may vary from about 1:1methyl lithium:nitrile up to about 5:1 methyl lithium:nitrile with anexcess of methyl lithium being preferred.

The hydrolysis reaction, for example: ##STR100## is carried out in thepresence of water and a weak protonic acid such as dilute sulfuric acidand dilute phosphoric acid, dilute ammonium chloride, or dilutehydrochloric acid or mixtures of same. In the hydrolysis reaction, it isnecessary to use sufficient aqueous acid such that a complete hydrolysisof the organometallic intermediates defined according to the structures:##STR101## occurs. At the end of the reaction, the solvents are strippedfrom the reaction mass, e.g. the diethylether and toluene remaining, andthe reaction product is fractionally distilled in order to either (a)insure a pure enough product for use as a tobacco flavorant or (b) inorder to insure a pure enough product for the subsequent reaction toform the solanone compound or mixture of compounds.

The dehydration of the compound defined according to the structure:##STR102## or the mixture of compounds defined according to thestructures: ##STR103## is carried out according to the reaction, forexample: ##STR104## The dehydration reaction is carried out in thepresence of a dehydrating agent, for example, phosphorous oxychloride ina pyridine solvent. The mole ratio of solanone hydrate:dehydrating agentmay vary from about 1:1 solanone hydrate:dehydrating agent up to about4:1 solanone hydrate:dehydrating agent. Obviously, where the excess ofsolanone hydrate is used, the unreacted distilled solanone hydrate isrecycled. Other dehydrating agents usable may be anhydrous aluminumchloride or concentrated sulfuric acid.

The dehydration reaction is carried out at a temperature in the range offrom about 30° C. up to about 120° C. with a preferred reactiontemperature being in the range of from 50° C. up to 100° C. At the endof the reaction, the reaction mass is "worked-up" by means of standardextraction, neutralization, drying and fractional distillation.

In using the nitrile intermediate defined according to the structure:##STR105## or the mixture of nitrile intermediates defined according tothe structure: ##STR106## to produce the norsolanadione definedaccording to the structure: ##STR107## the ketone moiety is first"ketalized" to form a ketal or a mixture of ketals defined according tothe structure: ##STR108## wherein one of the dashed lines is acarbon-carbon double bond and the other of the dashed lines is acarbon-carbon single bond and wherein R represents hydrogen or one of C₁-C₄ alkyl. This "ketalization" reaction; for example: is carried outusing, for example, ethylene glycol (wherein R is hydrogen);1,2-propylene glycol (wherein R is methyl) or 1,2-butylene glycol(wherein R is ethyl). Other ketals can be formed but these would beuneconomical, for example, ketals formed from 2,3-butylene glycol or2,3-pentylene glycol.

The temperature of the "ketalization" reaction is preferably between 25°C. and 45° C. The ketalization reaction is carried out in the presenceof an acid such as sulfuric acid or an acid ion exchange resin, e.g. apolystyrene sulfonic acid such as Amberlyst® 15 manufactured by the Rohm& Haas Corporation of Philadelphia, Pa. or paratoluene sulfonic acid. Itis preferable to carry out the ketalization reaction in the presence ofan additional reagent, trimethylorthoformate. Thus, the acidic reagentis preferably formed from mixing trimethylorthoformate and, for example,Amberlyst® 15. Then the reactants, for example, ethylene glycol orpropylene glycol are admixed with the ketone nitrile defined accordingto the structure: ##STR109## or mixture of same defined according to thestructure: ##STR110## Other acids which may be used in the ketalizationreaction are Lewis acids such as borontrifluoride diethyletherate,stannic chloride or zinc chloride with borontrifluoride diethyletheratebeing preferred. The mole ratio of ketone defined according to thestructure: ##STR111## or mixture of ketones defined according to thestructure: ##STR112## glycol such as ethylene glycol or propylene glycolmay vary from about 0.8:1 up to about 1:0.8 with a preferred mole ratioof 1:1. In summary, the ketalization reaction may be carried out in thepresence of protonic acids such as hydrochloric acid or ion exchangecatalysts such as Amberlyst® 15 or Lewis acids such as borontrifluoridediethyletherate or the like. At the end of the reaction, the reactionmass is stripped of solvent and fractionally distilled in order toinsure a substantially pure enough ketal to carry out the subsequentreaction leading to the formation of the norsolanadione.

Thus, in the next step of the reaction, the resulting ketal or mixtureof ketals defined according to the structure: ##STR113## is reacted withmethyl lithium according to the reaction, for example: ##STR114##wherein R represents hydrogen or C₁ -C₄ alkyl in order to form novelorganometallic intermediates, for example those defined according to oneof the structures: ##STR115## The temperature of reaction may vary fromabout -10° C. up to about +20° C. The reaction takes place in thepresence of an inert volatile solvent such as diethylether ortetrahydrofuran. The mole ratio of methyl lithium:ketal derivative mayvary from about 0.5:1 up to about 1:4. At the end of the reaction, thereaction product is hydrolyzed in the presence of a protonic acid suchas dilute hydrochloric acid, dilute sulfuric acid or dilute aqueousammonium chloride at a temperature in the range of from about 0° C. upto about 50° C.; most conveniently at ambient conditions; 20°-30° C. andatmospheric pressure according to the reaction; for example: ##STR116##wherein R is defined supra. The reaction mass is then "worked-up" as byextraction and fractional distillation in order to form a pure,organoleptically acceptable and toxicologically acceptable derivativeuseful in augmenting or enhancing the aroma or taste of smoking tobaccoboth prior to and on smoking.

During the step of hydrolysis of the organometallic ketal speciesdefined generally according to the structure: ##STR117## although themajor compound formed is norsolanadione defined according the thegeneric structure: ##STR118## (a mixture, wherein in the mixture one ofthe dashed lines is a carbon-carbon double bond and the other of thedashed lines is a carbon-carbon single bond) there is also formed amixture of compounds defined according to the structure: ##STR119##wherein in the mixture, one of the dashed lines is a carbon-carbondouble bond and the other of the dashed lines is a carbon-carbon singlebond and R represents hydrogen or C₁ -C₄ alkyl. This mixture is usuallyseparated from the reaction mass as by distillation and the componentsmay be separated from one another by fractional distillation in vacuuo.The resulting components are useful as intermediates for formingsolanadione in and of themselves, or they may be used as such foraugmenting or enhancing the aroma or taste of smoking tobaccos.

Furthermore, the ketals of our invention which are defined according tothe structure: ##STR120## wherein R represents hydrogen or C₁ -C₄ alkyland one of the dashed lines represents a carbon-carbon double bond andthe other of the dashed lines represents a carbon-carbon single bondincluding the compounds defined according to the structures: ##STR121##(hereinafter referred to as "keto ketals" produces as by-products of ourinvention are capable of supplying and/or potentiating certain flavorand aroma notes usually lacking in many tobacco flavors heretoforeprovided.

As used herein in regard to tobacco flavors, the terms "alter" and"modify" in their various forms means "supplying or imparting flavorcharacter or note to otherwise bland tobacco, tobacco substituents, ortobacco flavor formulations or augmenting the existing flavorcharacteristics where a natural flavor is deficient in some regard orsupplementing the existing flavor impression to modify its quality,character or taste".

As used herein, the term "enhance" is intended to mean theintensification (without change in kind of quality of aroma or taste) ofone or more taste and/or aroma nuances present in the organolepticimpression of tobacco or a tobacco substitute or a tobacco flavor.

Our invention thus provides an organoleptically improved smoking tobaccoproduct and additives therefor, as well as methods of making the samewhich overcome specific problems heretofore encountered in whichspecific desired Virginia-type tobacco aroma and taste nuances thereof,are created or enhanced and may be readily controlled and maintained atthe desired uniform level regardless of variations in the tobaccocomponents of the blend.

This invention further provides improved tobacco additives and methodswhereby various Virgina-type tobacco notes may be imparted to smokingtobacco products and may be readily varied and controlled to produce thedesired uniform flavor characteristics.

In carrying out this aspect of our invention, we add to smoking tobaccomaterials or a suitable substitute therefor (e.g. dried lettuce leaves)an aroma and flavor additive containing as an active ingredient a ketoketal(s) produced according to the process of our invention.

In addition to the keto ketal(s) produced according to the process ofour invention, other flavoring and aroma additives may be added to thesmoking tobacco materials or substitute therefor, either separately orin mixture with the keto ketal(s) produced according to the process ofour invention, as follows:

(i) Synthetic materials:

Beta-ethyl-cinnamaldehyde;

Beta-cyclohomocitral;

Eugenol;

Dipentene;

Beta-damascenone;

Beta-damascone;

Maltol;

Ethyl maltol;

Delta-undecalactone;

Delta-decalactone;

Benzaldehyde;

Amyl acetate;

Ethyl butyrate;

Ethyl valerate;

Ethyl acetate;

2-hexenol-1;

2-methyl-5-isopropyl-1,3-nonadiene-8-one;

2,6-dimethyl-2,6-undecadiene-10-one;

2-methyl-5-isopropyl acetophenone;

2-hydroxy-2,5,5,8a-tetramethyl-1-(2-hydroxyethyl)-decahydronaphthalene;

Dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1,b]-furan;

4-hydroxy hexanoic acid, gamma lactone and polyisoprenoid hydrocarbonsdefined in Example V of U.S. Pat. No. 3,589,372, issued on June 29,1971.

(ii) Natural oils:

Celery seed oil;

Coffee extract;

Bergamot oil;

Cocoa extract;

Nutmeg oil;

Origanum oil.

An aroma and flavoring concentrate containing keto ketal(s) producedaccording to the process of our invention and, if desired, one or moreof the above-indicated additional flavoring additives may be added tothe smoking tobacco material, to the filter or to the leaf or paperwrapper. The smoking tobacco material may be shredded, cured, cased andblended tobacco material or reconstituted tobacco material or tobaccosubstitutes (e.g. lettuce leaves) or mixtures thereof. The proportionsof flavoring additives may be varied in accordance with taste butinsofar as enhancement or the imparting of natural and/or sweet notes,we have found that satisfactory results are obtained if the proportionby weight of the sum total of the keto ketal(s) produced according tothe process of our invention to smoking tobacco material is between 250ppm and 1,500 ppm (0.025%-0.15%) of the active ingredients to thesmoking tobacco material. We have further found that satisfactoryresults are obtained if the proportion by weight of the sum total of theketo ketal(s) produced according to the process of our invention used toflavoring material is between 2,500 and 15,000 ppm (0.25%-1.5%).

Any convenient method for incorporating the keto ketal(s) producedaccording to the process of our invention in the tobacco product may beemployed. Thus, the keto ketal(s) produced according to the process ofour invention taken alone or along with other flavoring additives may bedissolved in a suitable solvent such as ethanol, pentane, diethyletherand/or other volatile organic solvents and the resulting solution mayeither be sprayed on the cured, cased and blended tobacco material orthe tobacco material may be dipped into such solution. Under certaincircumstances, a solution of the keto ketal(s) produced according to theprocess of our invention taken alone or taken further together withother flavoring additives as set forth above, may be applied by means ofa suitable applicator such as a brush or roller on the paper or leafwrapper for the smoking product, or it may be applied to the filter byeither spraying or dipping or coating.

Furthermore, it will be apparent that only a portion of the tobacco orsubstitute therefore need be treated and the thus treated tobacco may beblended with other tobaccos before the ultimate tobacco product isformed. In such cases, the tobacco treated may have the keto ketal(s)produced according to the process of our invention in excess of theamounts or concentrations above indicated so that when blended withother tobaccos, the final product will have the percentage within theindicated range.

In accordance with one specific example of our invention, an aged, curedand shredded domestic burley tobacco is sprayed with a 20% ethyl alcoholsolution of a 50:50 (mole:mole) ratio of compounds defined according tothe structures: ##STR122## in an amount to provide a tobacco compositioncontaining 800 ppm by weight of the keto ketal mixture on a dry basis.Thereafter the alcohol is removed by evaporation and the tobacco ismanufactured into cigarettes by the usual techniques. The cigarettes,when treated as indicated, have desired and pleasing aroma (increasedsmoke body sensation in the mouth with enhanced tobacco-like notes andpleasant aromatic nuances) which is detectable in the main and sidestreams when the cigarette is smoked. This aroma is described as havingsweet, fruity, Virginia tobacco-like notes.

While our invention is particularly useful in the manufacture of smokingtobacco such as cigarette tobacco, cigar tobacco and pipe tobacco, othertobacco products formed from sheeted tobacco dust or fines may also beused. Likewise, the keto ketal(s) produced according to the process ofour invention can be incorporated with materials such as filter tipmaterial, seam paste, packaging materials and the like which are usedalong with tobacco to form a product adapted for smoking. Furthermore,the keto ketal(s) produced according to the process of our invention canbe added to certain tobacco substitutes of natural or synthetic origin(e.g. dried lettuce leaves) and, accordingly, by the term "tobacco" asused throughout this specification is meant any composition intended forhuman consumption by smoking or otherwise, whether composed of tobaccoplant parts or substitute materials or both.

The following examples serve to illustrate our invention and theinvention is to be considered restricted thereto only as indicated inthe appended claims.

All parts and percentages given herein are by weight unless otherwisespecified.

EXAMPLE I Preparation of 4-(3-methyl-1-butenyl) morpholine

Reaction: ##STR123##

Into a 12 liter flask equipped with stirrer, Bidwell trap, thermometer,heating mantle, addition funnel and condenser is placed 2,200 ml ofcyclohexane and 2,180 grams (25 moles) of morpholine. The resultingmixture is heated to 50° C. and 2,155 grams of isovaleraldehyde areadded over a 1.5 hour period. An exotherm occurs and the solution beginsto reflux. Additional heat is applied and the refluxing is continueduntil no additional water is collected in the Bidwell trap. Thecyclohexane is then stripped off and the reaction product is distilledthrough a 1" stone packed column at total take-off yielding thefollowing fractions:

    ______________________________________                                                 Vapor   Liquid            Weight                                     Fraction Temp.   Temp.      Vacuum of Fraction                                Number   (°C.)                                                                          (°C.)                                                                             mm/Hg. (grams)                                    ______________________________________                                        1        55/70   80/90      4       51                                        2        75       95        4      442                                        3-9      80       95/140    4      2855                                       10       80      175        4      254                                        ______________________________________                                    

Fractions 3-9 are bulked for use in Example II.

EXAMPLE II Preparation of 4-isopropylglutaraldehydonitrile

Reactions: ##STR124##

Into a 22 liter flask equipped with stirrer, condenser, thermometer,heating mantle, addition funnel and nitrogen blanked is placed 2,855grams of bulked fractions 3-9 of the distillation product of thereaction product of Example I, the 4-(3-methyl-1-butenyl)morpholine and3,600 ml anhydrous ethyl alcohol. The resulting mixture is stirred andheated to reflux. 1,456 grams (27.4 moles) of acrylonitrile is added tothe reaction mass over a period of 1.5 hours. Reflux is continued untila GLC profile shows that more than 95% of the enamine has converted toproduct.

FIG. 1 is the GLC profile for the reaction mass at this point; prior tohydrolysis. The conditions are: SE-30 column programmed at 100°-220° C.at 8° C. per minute. The peak indicated by reference numeral "1" is thepeak for the starting material having the structure: ##STR125## The peakindicated by reference numeral "2" is the peak for the reaction producthaving the structure: ##STR126## The peak indicated by reference numeral"3" is the peak for the compound defined according to the structure:##STR127##

Reflux is continued and 4,600 ml of 5% aqueous hydrochloric acid isadded to the reaction mass over a 40 minute period. The reflux iscontinued and the reaction is monitored by GLC until no change isapparent (20 hours). The enamine adduct converts to product and thecyclobutane adduct converts to product over a somewhat longer period oftime. When the reaction is complete, three liters of water is added tothe reaction mass resulting in two phases, an organic phase and anaqueous phase. The organic phase is separated from the aqueous phase.The aqueous phase is washed once with one liter of dichloromethane andthe organic phases are combined. The organic phases are stripped ofsolvent and distilled on a 1" Goodloe packed column at a 9:1 refluxratio yielding the following fractions:

    ______________________________________                                                Vapor    Liquid            Weight of                                  Fraction                                                                              Temp.    Temp.      Vacuum Fraction                                   Number  (°C.)                                                                           (°C.)                                                                             mm/Hg. (grams)                                    ______________________________________                                        1       60/65    120        3.8     31                                        2       99       122        3.5     33                                        3       99       134        3.5    106                                         4-11   100/112  139/141    3.5    1869                                       12-14   105/90   141/225    3.0    775                                        ______________________________________                                    

Fractions 4-11 are bulked to yield 1,869 grams of product of 83% puritywhich is used in Example III, infra.

FIG. 2 is the GLC profile for the reaction product at the end of thereaction and prior to hydrolysis (conditions: SE-30 column programmed at100°-220° C. at 8° C. per minute). The peak indicated by referencenumeral "11" is the peak for the compound having the structure:##STR128##

The peak indicated by reference numeral "12" is for the compound havingthe structure: ##STR129##

FIG. 3 is the GLC profile for the reaction product subsequent tohydrolysis containing the compound defined according to the structure:##STR130##

FIG. 4A is the GLC profile for the distillation product of the reactionproduct of Example II, bulked fractions 4-11 containing the compoundhaving the structure: ##STR131##

FIG. 4B is the GLC profile for fraction 2 of the distillation product ofthe reaction product of Example II containing the compound having thestructure: ##STR132## (conditions: 10'×1/8" SE-30 column programmed at150°-220° C. at 8° C. per minute).

EXAMPLE III Preparation of 4-isopropyl-7-oxo-5-octenenitrile

Reaction: ##STR133##

Into a 2-liter flask equipped with stirrer, condenser, thermometer,heating mantle, Buchner funnel and Bidwell apparatus is placed 496 grams(2.9 moles) of 4-isopropylglutaraldehydonitrile, bulked fractions 4-11,prepared according to the procedure of Example II; 850 grams (14.7moles) of acetone and 100 grams (0.59 moles) of barium hydroxidemonohydrate.

The resulting mixture is stirred and heated to reflux and refluxed for aperiod of 10 hours. After cooling to room temperature, the reaction massis filtered to remove the barium hydroxide. The excess acetone isremoved from the reaction mass in vacuum (150 mm/Hg vacuum). Theresulting crude oil weight is 592 grams.

The residual oil is placed in a 2-liter flask equipped with a Bidwelltrap and reflux condenser. 600 ml toluene and 20 grams of oxalic acidare then added to the reaction mixture and the resulting mixture isheated to reflux for a period of 2 hours until no more water is evolved.After cooling, the resulting reaction mass is washed with 600 ml waterfollowed by 500 ml of a saturated sodium bicarbonate solution followedby 500 ml of a saturated sodium chloride solution.

The crude reaction product is then stripped of solvent and distilled ona 2.5" Splash column yielding the following fractions:

    ______________________________________                                               Vapor    Liquid          Weight of                                     Fraction                                                                             Temp.    Temp.    Pressure                                                                             Fraction                                                                              Product                               Number (°C.)                                                                           (°C.)                                                                           mm/Hg. (grams) %                                     ______________________________________                                        1       98-105  129-132  1      14.4    44                                    2      105-120  132-143  1      42.8    73                                    3      120-127  143-153  1      131.4   91                                    4      127-150  153-193  1      98.4    94                                    5      150-190  193-238  1      40.4                                          ______________________________________                                    

FIG. 5 is the GLC profile for the crude reaction product after refluxingfor 10 hours (conditions: 10'×1/8" SE-30 column programmed at from150°-220° C. at 8° C. per minute). The peak indicated by referencenumeral "21" on FIG. 5 is for the compound defined according to thestructure: ##STR134## the starting material.

The peak indicated by reference numeral "22" is for the compound definedaccording to the structure: ##STR135##

The peak indicated by reference numeral "23" is for the product definedaccording to the structure: ##STR136##

The peak indicated by reference numeral "24" is for the product havingthe structure: ##STR137##

FIG. 6 is the GLC profile for bulked fractions 1-4 of the distillationproduct of the reaction product of this example (conditions: SE-3010'×1/8" column programmed at 150°-220° C. at 8° C. per minute).

EXAMPLE IV Preparation of 4-isopropyl-7-oxo-5-octenenitrile

Reaction: ##STR138##

Into a 500 cc reaction vessel equipped with stirrer, condenser,thermometer, and heating mantle is placed 1.0 moles ofgluteraldehydonitrile (bulked fractions 4-11 of Example III); 2.0 molesof acetone and 0.05 liters of a one molar aqueous solution of sodiumhydroxide. The reaction mass is stirred for a period of five hours andthen heated at 50°-60° C. for an additional five hours. The reactionmass is then cooled to room temperature and 200 cc of water is addedwith stirring. The reaction mass is then neutralized with a 50% aqueoussolution of acetic acid. The organic phase is separated from the aqueousphase and the organic phase is washed with two 200 cc portions of waterfollowed by one 200 cc portion of 10% sodium bicarbonate solution. Thereaction mass is dried over anhydrous magnesium sulfate and stripped ofsolvent. The reaction mass is then distilled on a 12" stone-packedcolumn yielding the following fractions:

    ______________________________________                                                  Vapor   Liquid            Weight of                                 Fraction  Temp.   Temp.      Pressure                                                                             Fraction                                  Number    (°C.)                                                                          (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1         50/90   120/140    0.5/0.4                                                                              11.0                                      2         135     155        0.4    22.0                                      3         138     189        0.6    40.0                                      4         178     250        0.7    14.0                                      ______________________________________                                    

EXAMPLE V Preparation of 4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR139##

Into a 2-liter reaction vessel equipped with stirrer, condenser,thermometer, dropping funnel and heating mantle is placed 250 mlanhydrous methanol and 5 grams (0.089 moles) of potassium hydroxidepellets. The potassium hydroxide is dissolved in the methanol. From thedropping funnel, 137.0 grams (1.0 moles) of glutaraldehydonitrile(bulked fractions 4-11 of Example III) is added over a period of 0.5hours. The reaction mass temperature is at 30° C. and is heated to 40°C. While maintaining the reaction mass at 40° C., from the droppingfunnel, 174 grams (3.0 moles) of acetone is added to the reaction massfrom the dropping funnel.

The reaction mass is then refluxed for a period of three hours and GLCanalysis indicates that the reaction is complete. The reaction mass isthen cooled to room temperature and 200 cc of water is added. Thereaction mass is then neutralized with a 50% aqueous solution of aceticacid (25 ml). The reaction mass is extracted with diethylether and thediethylether extracts are washed with two 100 cc portions of waterfollowed by one 100 cc portion of sodium bicarbonate solution. Theresulting material is dried over anhydrous magnesium sulfate, strippedof solvent and distilled on a 2" Splash column yielding the followingfractions:

    ______________________________________                                                 Vapor    Liquid            Weight of                                 Fraction Temp.    Temp.      Pressure                                                                             Fraction                                  Number   (°C.)                                                                           (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1        100/120  145/175    2.0/5.0                                                                              11.0                                      2        135      200        5.0    24.0                                      3        140      240        5.0     1.0                                      ______________________________________                                    

FIG. 7A is the GLC profile for the crude reaction product containing thecompound having the structure: ##STR140##

FIG. 7B is the GLC profile for the distillation product of the foregoingdistillation (conditions: SE-30 column programmed at 100°-220° C. at 8°C. per minute). This material contains the compound having thestructure: ##STR141##

FIG. 8 is the infra-red spectrum for the compound having the structure:##STR142## produced according to this example.

EXAMPLE VI Preparation of 4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR143##

Into a 500 cc reaction flask equipped with stirrer, condenser,thermometer and heating mantle is placed 66 cc of a one-molar aqueoussolution of sodium hydroxide and 154.0 grams (1.125 moles) ofglutaraldehydonitrile (bulked fractions 4-11 of Example III). From thedropping funnel, 130.5 grams (2.25 moles) of acetone is added over aperiod of 15 minutes to the reaction mass with stirring. After additionof the acetone, the reaction mass is heated to 50°-60° C. and maintainedat 50°-60° C. for a period of 2.5 hours while being monitored using GLC.The reaction mass is complete at the end of the 2.5 hour period. Thereaction mass is then cooled to room temperature and 200 cc of water isadded with stirring. The reaction mass is then neutralized with 65 cc ofa 50% aqueous acetic acid solution. The organic phase is then separatedfrom the aqueous phase and the organic phase is washed with one 200 ccof portion of water followed by one 200 cc portion of a 10% sodiumbicarbonate solution. The resulting product is dried over anhydrousmagnesium sulfate, stripped of solvent and distilled on a 12"stone-packed column yielding the following fractions:

    ______________________________________                                                  Vapor   Liquid            Weight of                                 Fraction  Temp.   Temp.      Pressure                                                                             Fraction                                  Number    (°C.)                                                                          (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1         95/120  160/165    2.0/2.0                                                                               5.0                                      2         140     165        2.0    15.0                                      3         145     180        2.0    25.0                                      4         150     210        2.0    24.0                                      5         150     230        2.0    12.0                                      ______________________________________                                    

FIG. 9 is the GLC profile for the crude reaction product containing thecompound having the structure: ##STR144##

FIG. 10 is the GLC profile for the reaction product immediately prior todistillation (conditions: SE-30 column programmed at 100°-220° C. at 8°C. per minute).

EXAMPLE VII Preparation of 4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR145##

Into a 5-liter reaction flask equipped with stirrer, reflux condenser,addition funnel and thermometer is placed 490 ml of a one-molar solutionof sodium hydroxide and 1,250 grams (9.15 moles) of4-isopropylglutaraldehydeonitrile (bulked fractions 4-11 of ExampleIII). 1,062 grams (18.3 moles) of acetone is added over a period of 0.75hours from the dropping funnel. After addition of the acetone, thereaction mass is heated to 60° C. and the progress of the reaction ismonitored using GLC. When the conversion to product is complete; at theend of two hours, a solution of 30 grams of acetic acid in 1,600 ml ofsaturated sodium chloride is added over a fifteen minute period to thereaction mass. The resulting reaction product has two phases; an organicphase and an aqueous phase. The organic phase is separated from theaqueous phase. The organic phase is washed with one liter of 10% sodiumbicarbonate solution. The organic phase is then distilled on a 12" stonesaddle-packed column yielding the following fractions:

    ______________________________________                                                   Vapor    Liquid           Weight of                                Fraction   Temp.    Temp.     Pressure                                                                             Fraction                                 Number     (°C.)                                                                           (°C.)                                                                            mm/Hg. (grams)                                  ______________________________________                                        1           90/110  140/160   2.0    13                                       2          130      165       2.0    15                                       3-8 (bulked)                                                                             145/165  165/220   2.0    464                                      ______________________________________                                    

Bulked fractions 3-8 are placed in a two-liter flask. 500 ml toluene and2.5 grams oxalic acid are then added. The flask is set up with a Bidwelltrap and condenser and the contents are refluxed until no additionalwater collects in the trap. The resulting mixture is cooled to be usedin the next reaction.

FIG. 11 is the infra-red spectrum for the compound defined according tothe structure: ##STR146## prepared according to this example.

EXAMPLE VIII Preparation of8-hydroxy-5-isopropyl-8-methyl-non-6-en-2-one

Reactions: ##STR147##

Into a 12-liter reaction vessel equipped with stirrer, thermometer,condenser, gas addition tube (straight, not a dispersion tube), heatingmantle and nitrogen blanket apparatus, is placed 4.5 liters ofdiethylether anhydrous and 120 grams (17.4 moles) of 4-16 mesh lithiumshot. The contents of the flask are stirred and refluxed for one hour inorder to activate the lithium. The heating mantle is removed and thecontents of the flask are allowed to cool to room temperature. 828 grams(8.7 moles) of methyl bromide gas is then added to the reaction massover a six hour period at a rate such that little gas escapes from thetop of the condenser. The reaction is exothermic and will cause thesolvent to reflux. When the addition of the methyl bromide is completeand the lithium has dissolved, one liter of toluene is added to thereaction mass. The resulting mixture is cooled to 0°-5° C. and the gasaddition tube is replaced by an addition funnel. A toluene solutioncontaining 470 grams of 4-isopropyl-7-oxo- 5-octene-nitrile preparedaccording to Example IV is added dropwise to the reqction mass over aone hour period while maintaining the reaction mass at 0°-5° C. Whenaddition is complete, the reaction mass is allowed to warm to roomtemperature. A GLC sample at this point shows no starting material andno nitrile present. When the reaction is complete, 800 ml of saturatedammonium chloride solution is added to the reaction mass with stirring.The resulting mixture is stirred for one hour and the organic layer isseparated from the aqueous layer. The diethylether solvent is strippedfrom the reaction mass and the reaction mass is distilled through an 8"stone-packed column yielding the following fractions:

    ______________________________________                                                 Vapor    Liquid            Weight of                                 Fraction Temp.    Temp.      Pressure                                                                             Fraction                                  Number   (°C.)                                                                           (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1        120/125  150/160    0.9    38                                        2        130      165        0.9    72                                        3        135      165        0.9    102                                       4        140      225        1.2    72                                        ______________________________________                                    

Fractions 2-4 are bulked (246 grams, 45% of theory) and used for thenext step in Example IX.

FIG. 12 is the GLC profile for the crude reaction product containing thecompound having the structure: ##STR148## (conditions: SE-30 columnprogrammed at 100°-220° C. at 8° C. per minute).

FIG. 13 is the infra-red spectrum for the compound defined according tothe structure: ##STR149## produced according to this example.

EXAMPLE IX Preparation of solanone

Reaction: ##STR150##

Into a five-liter reaction flask equipped with stirrer, thermometer,condenser, addition funnel, nitrogen blanket apparatus and cooling bathis placed 437 grams (5.5 moles) of pyridine. 720 grams (3.4 moles) of8-hydroxy-5-isopropyl-8-methyl-non-6-en-2-one produced according toExample VIII (bulked fractions 2-4) is added to the reaction mass in oneportion. The resulting mixture is stirred and 229 grams (1.5 moles) ofphosphorus oxychloride is added dropwise from the addition funnel over aperiod of one hour. The reaction is exothermic and the temperature risesto 50° C. where it is controlled by means of a dry ice-isopropyl alcoholbath. After half of the addition of the phosphorous oxychloride, thereaction becomes substantially less exothermic. When addition iscomplete, the cooling bath is removed and the mixture is stirred for oneadditional hour during which time a precipitate forms. The mixture isheated to 100° C. to dissolve the precipitate. The source of heating isremoved and one liter of water is added dropwise to the reaction mass.The reaction mass is then cooled to room temperature and is now existingin two phases; an aqueous phase and an organic phase.

The aqueous phase is removed from the organic phase and the aqueousphase is extracted twice with 500 ml portions of cyclohexane. Theorganic layers are combined and extracted with three 300 ml portions of10% aqueous hydrochloric acid and then washed with two 300 ml portionsof water and two 300 ml portions of saturated sodium bicarbonatesolution. The solvent is stripped and the product is distilled through a2" Splash column yielding the following fractions:

    ______________________________________                                                 Vapor    Liquid            Weight of                                 Fraction Temp.    Temp.      Pressure                                                                             Fraction                                  Number   (°C.)                                                                           (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1        110-115  120        1.8     16                                       2-5      115-120  140-180    1.0    350                                       6        125      210        1.0    120                                       ______________________________________                                    

Fractions 2-6(weighing 470 grams) are redistilled on a 4' Vigreux column(8 plates) yielding the following fractions:

    ______________________________________                                                  Vapor   Liquid            Weight of                                 Fraction  Temp.   Temp.      Pressure                                                                             Fraction                                  Number    (°C.)                                                                          (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1         45/80    90/110    0.9    11                                        2-5       82-85   110/112    0.9    83                                        6-10      85-88   112-130    0.8    331                                       11        100     146        0.8    26                                        12        110     162        0.9    24                                        ______________________________________                                    

Fractions 6-10 are bulked and utilized for their organoleptic propertiesin creation of a tobacco flavor.

FIG. 14 is the GLC profile for bulked fractions 6-10 of the distillationproduct above (conditions: Carbowax column programmed at 100°-220° C. at8° C. per minute). The peak indicated by reference numeral "31" is forthe compound having the structure: ##STR151## The peak indicated byreference numeral "32" is for the compound having the structure:##STR152## The peak indicated by reference numeral "33" is for thestarting material having the structure: ##STR153##

EXAMPLE X Preparation of ethylene glycol ketal of4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR154## (wherein R represents hydrogen).

Into a one-liter reaction flask equipped with stirrer, reflux condenser,thermometer and heating mantle is placed 239 grams oftrimethylorthoformate and 20 grams of Amberlyst® 15 polystyrene sulfonicacid catalyst manufactured by the Rohm & Haas Company of Philadelphia,Pa. Into the resulting mixture, with stirring, is placed 141 grams ofethylene glycol. The reaction mass is warmed to 25° C. While maintainingthe reaction mass at 25° C. with stirring, over a period of 15 minutes,358 grams of 4-isopropyl-7-oxo-7-octenenitrile (bulked fractions 3-5) isadded to the reaction mass. A mild exotherm results. The reaction massis cooled in order to maintain the temperature at 30°-35° C.

The reaction mass is then aged with stirring for 2.75 hours during whichtime samples are taken and analyzed using GLC analysis.

When the reaction is complete, the catalyst is separated from thereaction mass using a Buchner funnel and a side-arm flask containing 20grams of calcium carbonate. The calcium carbonate is filtered and thecrude ketal is stripped of solvent using a rotary evaporator. The ketalis then distilled to yield the following fractions:

    ______________________________________                                                  Vapor   Liquid           Weight of                                  Fraction  Temp.   Temp.     Pressure                                                                             Fraction                                   Number    (°C.)                                                                          (°C.)                                                                            mm/Hg. (grams)                                    ______________________________________                                        1         110     110       2/2    22                                         2         134     150       2      101                                        3         131     151       2      94                                         4         134     155       2      106                                        5         128     205       2      83                                         ______________________________________                                    

FIG. 15 is the GLC profile for the crude reaction product. The peakindicated by reference numeral "41" is for the compounds definedaccording to the structure: ##STR155##

FIG. 16 is the NMR spectrum for the peak indicated by reference numeral"41" of FIG. 15 of this example for the compound having the structure:##STR156##

EXAMPLE XI Preparation of norsolanadione

Reactions: ##STR157## (wherein R represents hydrogen).

Into a 5,000 ml reaction flask equipped with stirrer, thermometer,reflux condenser and heating mantle is placed 66 grams of methyllithium. The methyl lithium is cooled to 0° C. From an addition funnel,while maintaining the reaction mass at 0°-20° C., bulked fractions 2-5(557.5 grams) of the ketal reaction product prepared according toExample X is added to the methyl lithium. The addition is carried outover a period of one hour. At the end of the one hour period, the feedof the ketal is complete and the reaction mass is quenched with waterfollowed by 1,000 ml aqueous 10% hydrochloric acid. The reaction mass isthen combined with 300 ml concentrated hydrochloric acid causing the pHto drop to 1. The organic phase is separated from the aqueous phase andthe organic phase is washed with one liter of 10% sodium carbonatefollowed by saturated sodium chloride solution. The diethylether isremoved on a roto-evaporator.

FIG. 17 is the NMR spectrum for the compound having the structure:##STR158## produced according to this example.

EXAMPLE XII Production of norsolanadione

Reactions: ##STR159## (wherein R represents hydrogen).

Into a 12 liter reaction flask equipped with nitrogen blanket apparatus,stirrer, thermometer and reflux condenser is placed 88 grams (4.0 moles)of methyl lithium dissolved in 400 cc of diethylether. The diethylethersolution of methyl lithium is cooled to 0° C. and over a period of 2hours, 459 grams of the ketal of Example X is added dropwise to themethyl lithium solution while maintaining the reaction temperature at0°-5° C. When the reaction is complete, the reaction mass is quenchedwith two liters of a 6 molar aqueous hydrochloric acid solution and thereaction mass is cooled whereby the temperature is maintained at 5°-15°C. The reaction mass is then washed with one 1,000 ml portion ofsaturated sodium carbonate followed by one 1,000 ml portion of waterfollowed by one 1,000 ml portion of saturated aqueous sodium chloridesolution. The organic layer is stripped of solvent using a rotaryevaporator and the solvent is distilled yielding the followingfractions:

    ______________________________________                                               Vapor    Liquid                 Weight of                              Fraction                                                                             Temp.    Temp.    Pressure                                                                              Reflux                                                                              Fraction                               Number (°C.)                                                                           (°C.)                                                                           mm/Hg.  Ratio (grams)                                ______________________________________                                        1      93/110   142/142  3.0     9:1   28                                     2      122      145      3.0     9:1   31                                     3      125      147      3.0     9:1   16                                     4      125      150      2.7     9:1   23                                     5      122      144      2.4     9:1   23                                     6      123      143      2.4     9:1   15                                     7      122      155      2.4     9:1   21                                     8      125      158      3.0     9:1   31                                     9      125      160      3.0     9:1   18                                     10     124      166      3.0     9:1   43                                     11     125      195      3.0     9:1   18                                     12     120      230      3.0     9:1   13                                     ______________________________________                                    

FIG. 18 is the infra-red spectrum for the norsolanadione.

FIG. 19 is the mass spectrum for fraction 3 of the foregoingdistillation product for norsolanadione.

EXAMPLE XIII Preparation of 1,2-propylene glycol ketal of4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR160## (wherein R represents methyl).

Into a 2,000 ml reaction flask equipped with stirrer, condenser,thermometer and heating mantle is placed 318 grams oftrimethylorthoformate and 25 grams of borontrifluoride diethyletherate.While maintaining the reaction mass at a temperature of 5° C. and over a15 minute period, 228 grams of propylene glycol is added to theresulting mixture with cooling and stirring from the dropping funnel.The reaction mass is then heated to 40° C. and over a two hour period,while maintaining the reaction mass at 40°-50° C., the reaction productof Example VII, bulked fractions 3-8,(4-isopropyl-7-oxo-7-octenenitrile) (537 grams) is added to the reactionmass with stirring. At the end of the addition of the4-isopropyl-7-oxo-7-octenenitrile, the reaction mass is quenched into1,000 ml saturated aqueous sodium carbonate solution. The organic phaseis separated from the aqueous phase and the organic phase is washed with10% sodium chloride to neutral (pH=7). The crude reaction mass is thendistilled yielding the following fractions:

    ______________________________________                                                 Vapor   Liquid            Weight of                                  Fraction Temp.   Temp.      Pressure                                                                             Fraction                                   Number   (°C.)                                                                          (°C.)                                                                             mm/Hg. (grams)                                    ______________________________________                                        1        26/25   45/70      3/3     65                                        2        125     150        3      236                                        3        120     122        3      217                                        4        128     194        3      136                                        ______________________________________                                    

FIG. 20 is the GLC profile for the crude reaction product.

EXAMPLE XIV Preparation of 1,2-propylene glycol ketal of4-isopropyl-7-oxo-7-octenenitrile

Reaction: ##STR161## (wherein R represents methyl).

Into a one liter reaction flask equipped with stirrer, thermometer,reflux condenser, heating mantle and cooling bath is placed 130 grams oftrimethylorthoformate and 3 drops of concentrated hydrochloric acid.Over a five minute period 92 grams of propylene glycol is slowly addedto the reaction mass which exotherms to 5° C. while applying the coolingbath. Over a period of 15 minutes, while maintaining the reaction massat 14°-16° C., 198 grams of bulked fractions 3-8 of the distillationproduct of the reaction product of Example VII is added to the reactionmass (a composition of matter consisting primarily of the compoundhaving the structure: ##STR162## 15 drops of concentrated hydrochloricacid is then added to the reaction mass which exotherms to 36° C. Thereaction mass is stirred for a period of 1.5 hours at a temperature of36°-40° C. The reaction mass is then poured into 500 ml of 5% aqueoussodium bicarbonate. The aqueous phase is separated from the organicphase and the organic phase weighs 290 grams. The organic phase is thendried over anhydrous magnesium sulfate and distilled yielding thefollowing fractions:

    ______________________________________                                                 Vapor    Liquid            Weight of                                 Fraction Temp.    Temp.      Pressure                                                                             Fraction                                  Number   (°C.)                                                                           (°C.)                                                                             mm/Hg. (grams)                                   ______________________________________                                        1        103/122  141/150    2.6/2  50                                        2        121      151        1.6    50                                        3        119      151        1.5    50                                        4        119      155        1.5    50                                        5        125      215        1.4    85                                        ______________________________________                                    

FIG. 21 is the GLC profile for the reaction product of Example XIV.

FIG. 22 is the NMR spectrum for fraction 5 of the foregoing distillationproduct containing the compound having the structure: ##STR163##

FIG. 23 is the infra-red spectrum for fraction 5 of the foregoingdistillation product containing the compound having the structure:##STR164##

EXAMPLE XV Preparation of norsolanadione

Reactions: ##STR165## (wherein R represents methyl).

Into a 500 ml reaction flask equipped with nitrogen blanket apparatus,cooling bath, reflux condenser, thermometer and stirrer is placed 110 mlof a 1.6 molar solution of methyl lithium in diethylether. The methyllithium solution is cooled to 0° C. and over a 30 minute period, theketal of fraction 5 of the distillation product of Example XIV (35grams) is added to the reaction mass. The reaction mass is then stirredfor a period of 2 hours at 0° C.

The reaction mass is then quenched with 150 ml of a 3M aqueous solutionof hydrochloric acid in a 50:50 mixture of methanol and water. 100 ml ofsaturated aqueous sodium chloride is then added to the reaction masswhich is transferred to a separatory funnel. An additional 50 ml ofaqueous saturated sodium chloride is added whereupon the layers exist intwo phases; an organic phase and an aqueous phase. The organic phase isseparated from the aqueous phase and washed with 150 ml of 5% aqueoussodium bicarbonate solution followed by 150 ml of saturated sodiumchloride solution. The solvent is stripped on a Rotovap evaporatoryielding 19.5 grams of crude reaction product.

The crude reaction product is then distilled yielding norsolanadione ata vapor temperature in the range of 122°-125° C.; a liquid temperaturein the range of 144°-158° C.; and a vacuum of 2.4-3.0 mm/Hg.

FIG. 24 is the GLC profile for the crude reaction product prior todistillation (conditions: Carbowax column programmed at 150°-220° C. at8° C. per minute).

FIG. 25 is the infra-red spectrum for the norsolanadione having thestructure: ##STR166##

EXAMPLE XVI Tobacco formulation

A tobacco mixture is produced by admixing the following ingredients:

    ______________________________________                                        Ingredients     Parts by Weight                                               ______________________________________                                        Bright          40.1                                                          Burley          24.9                                                          Maryland         1.1                                                          Turkish         11.6                                                          Stem (flue-cured)                                                                             14.2                                                          Glycerine        2.8                                                          Water            5.3                                                          ______________________________________                                    

The following flavor formulation is prepared:

    ______________________________________                                        Ingredients    Parts by Weight                                                ______________________________________                                        Ethyl butyrate  0.05                                                          Ethyl valerate  0.05                                                          Maltol          2.00                                                          Cocoa extract  26.00                                                          Coffee extract 10.00                                                          Ethyl alcohol  20.00                                                          Water          41.90                                                          ______________________________________                                    

The above stated tobacco flavor formulation is applied at the rate of1.0% to all cigarettes produced using the above tobacco formulation.Half of the cigarettes are then treated with 500 or 1,000 ppm of thecompound defined according to the structure: ##STR167## which is adistillation by-product (fraction 12 of the distillation product of thereaction product of Example XII boiling at 120° C. vapor temperature at3.0 mm/Hg pressure). The control cigarettes not containing said ketoketal produced according to Example XII and the experimental cigaretteswhich contain the keto ketal of Example XII are evaluated by pairedcomparison and the results are as follows:

The experimental cigarettes are found to have more body in tobacco smokeflavor and a fuller body sensation. The tobacco-like notes are enhancedand the flavor of the tobacco on smoking is more aromatic with floral,hay, tea-like, sweet and fruity aroma and taste nuances.

The tobacco smoke flavor of the experimental cigarettes, prior tosmoking, has floral, sweet and fruity notes. All cigarettes areevaluated for smoke flavor with a 20 mm cellulose acetate filter. Thesame results are obtained when using the propylene glycol ketal producedas a by-product of Example XV having the structure: ##STR168## boilingat 120° C. at 2.8 mm/Hg pressure.

What is claimed is:
 1. A process for preparing solanone comprising thesteps of reacting acetone with an aldehyde having the structure:##STR169## whereby at least one compound defined according to thestructure: ##STR170## is formed, said reaction being carried out in thepresence of base, wherein one of the dashed lines is a carbon-carbondouble bond and the other of the dashed lines is a carbon-carbon singlebond; reacting at least one compound defined according to the structure:##STR171## with methyl lithium in order to form at least one compoundselected from the group consisting of: ##STR172## reacting at least oneof the compounds having the structures: ##STR173## with aqueous acid inorder to form at least one compound having a structure selected from thegroup consisting of: ##STR174## and dehydrating at least one of thecompounds having the structure: ##STR175## in order to form at least onecompound having a structure selected from the group consisting of:##STR176##